National Sleep Foundation

Navigation

Chapter 5: Circadian Rhythm Sleep Disorders

Assessment and Diagnosis

Assessment and diagnosis of non-24 hour sleep wake disorder

All circadian rhythm sleep disorders require a similar clinical assessment that includes a complete sleep history.

Aanalysis of the patient’s sleep-wake schedule for at least one week (preferably 14 days), using a sleep log or actigraph, should be used to identify potential variations in sleep timing. For blind patients, a longer period of sleep log and actigraph recording is useful. It will also rule out other sleep disorders, such as insomnia, that are often mistaken for circadian rhythm sleep disorders.60 Polysomnography can also be used to rule out other sleep disorders.61

It is also important, for sighted individuals, to rule out underlying psychiatric conditions such as depression or personality disorders, which may increase the risk for Non-24.62 63

People with Non-24 show a progressive “pattern of sleep and wake times [that] typically delay each day with a period longer than 24 hours.”64